Senior Palestinian officials said last night that a move is afoot among leaders of the Palestinian Authority, led by Mahmoud Abbas (Abu Mazen) and Ahmed Qureia (Abu Ala), whereby Abu Mazen would replace Yasser Arafat as chairman of the Palestinian Authority after he is flown abroad for medical treatment, or alternatively, after his death. Abu Ala would continue in his current role as prime minister.

Prime Minister Ariel Sharon promised yesterday that Arafat will be able to return to the territories after completing his medical treatment in France.

But the working assumption among Israeli officials is that Arafat is terminally ill, meaning the issue of his return might never arise.

"From our standpoint, he is dead politically, even if he is not dead physically," said one defense establishment official.

Arafat will be flown to Jordan early this morning and then to Paris, where he will receive medical treatment, his doctors decided yesterday.

Over the last two days, Arafat's associates had said he would not agree to leave Ramallah without a pledge from Israel guaranteeing his ability to return.

Palestinian sources said that Arafat, 75, was in serious but stable condition following the sharp deterioration in his health Wednesday night. And in the PA's first public statement about what ails their aging leader, senior PA negotiator Saeb Erekat said last night that Arafat is suspected of having leukemia.

Officially, the PA broadcast reassurances yesterday: In the morning, Arafat aides announced that the chairman had sent a message to his people that his condition was good and there was no reason to worry. In the evening, the PA released pictures, which it said had been taken yesterday morning, of a smiling Arafat posing with his doctors. PA spokesmen also insisted that Arafat had walked about and even said his morning prayers.

Off the record, however, senior Palestinian officials said Arafat's mind was not functioning and he was unaware of his surroundings. Though his physical condition has improved since he lost consciousness Wednesday evening, they said, he was unable to recognize two of his top lieutenants - Prime Minister Ahmed Qureia and former prime minister Mahmoud Abbas - when they were summoned to his side. One senior PA official described Arafat's current mental state as "chronic weakness from which it is not clear that he can recover."

In addition, the officials said, he is physically very weak, unable to walk, and spent most of yesterday sleeping, aside from medical checks performed by the Jordanian, Egyptian and Tunisian doctors attending him. He is also feverish and has trouble digesting food.

Two doctors queried by Haaretz said that in order to have any chance of recovery, Arafat needs to be in intensive care in a very good hospital.

At a briefing for reporters given several hours before Erekat's revelation, Arafat spokesman Nabil Abu Rudeineh stuck to the story that the PA has adhered to for the last 10 days: that Arafat is merely "tired and in need of rest." He declined to give any further medical details.

But one of Arafat's doctors, also speaking several hours before Erekat's interview with Sky News, told Agence France-Presse that the Palestinian leader was suffering from a potentially fatal blood disorder that requires more tests to determine its cause. "His blood cells, which should normally destroy microbes, are currently destroying blood platelets," the doctor said on condition of anonymity. He added that this disorder could have been triggered "by an inflammation caused by a virus, a cancer or blood poisoning."

"The doctors think that he must be transferred abroad for further examinations in order to receive the care needed, for he could die if the condition persists," the doctor said.

A Jordanian helicopter will take Arafat from Ramallah to Amman this morning. The French presidency said that France would send a plane to Amman to convey him to Paris.

Arafat's wife, Suha, who has been living in Paris for the last eight years, made the reverse journey yesterday, arriving in Ramallah last night for her first visit with her husband in more than four years.

Arafat has never appointed a deputy or an heir, and even now, as he is preparing to be hospitalized abroad, he does not plan to name one, a PA spokesman said. But in backroom discussions among the PA's top leadership, Abbas (Abu Mazen) has repeatedly been mentioned as the person who will temporarily fill the vacuum created by Arafat's absence. Abbas, who is secretary-general of the PLO's executive committee, is second to Arafat in the PLO's hierarchy, and since the PLO is formally above the PA, this makes him a logical candidate for the job.

Senior Palestinian officials confirmed last night that a move is underway among the PA's leadership to have Abbas take over as acting chairman as soon as Arafat leaves for Paris, with Qureia continuing in his current role as prime minister. Under the PA's constitution, the person who is supposed to replace an incapacitated chairman is the speaker of the Palestinian parliament, but the current holder of this post, Rawhi Fatuh, is considered too anonymous a personage to fill the role adequately. Abbas and Qureia therefore plan to ask the parliament to convene in special session and rush through legislation enabling Abbas's appointment.

On Wednesday, Al Jazeera television had reported that a three-man committee, consisting of Abbas, Qureia and Fatuh, would run Palestinian affairs until Arafat recovers. But senior PA officials denied this report, and Fatuh left Ramallah for the Gaza Strip yesterday in an effort to mediate between rival militant groups.